Edge sealant formulation for wood-based panels

ABSTRACT

In one aspect, the present invention provides a formulation for sealing the edge of a wood-based panel. The formulation includes a butylacrylate latex, a solution of a wax in oil, a surfactant, and water. In another aspect of the invention, a wood-based panel that is edge-sealed with a sealant formulation is provided.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a division of U.S. continuation-in-partpatent application Ser. No. 09/619,010, which is a continuation-in-partof copending U.S. provisional patent application Serial No. 60/144,605,filed Jul. 20, 1999, expressly incorporated herein by reference in itsentirety, the benefit of the priority of which is hereby claimed under35 U.S.C. § 119.

FIELD OF THE INVENTION

[0002] The present invention relates to a formulation for sealingoriented strandboard edges to prevent edge swelling.

BACKGROUND OF THE INVENTION

[0003] Oriented strandboard (OSB) panels are commonly used as subfloorsheathing in residential homes. These panels are installed directly ontop of floor joists prior to installation of the walls and roof of thestructure. Thus, the subfloor is exposed to external environmentalconditions for a period of time during the general process of building ahouse. It is common for the subfloor panels to be subjected to rainduring this process. Sill plates, which vertically protrude from theperimeter of the floor, can literally convert the floor into a basin. Anuncovered subfloor can accumulate as much as two inches of water duringa rainstorm. In some cases the accumulated water will be left to absorbinto the subfloor panels for several days during the home-buildingprocess.

[0004] Unfortunately, exposure to water causes most OSB panels toundergo severe, irreversible thickness swell. Panels, which aremanufactured at a thickness of 720 mils (0.720 inch), can actually swellto edge thickness values in excess of 1000 mils. Upon drying, these samepanels will typically have an edge thickness of approximately 900 mils.The worst aspect of the swelling behavior is that the OSB swells to agreater extent on the edge of the panel than it does in regions towardsthe center of the panel. Panels subjected to a wet and redry cycle canbe 20 to 150 mils thicker at the panel edges than they are 4 inchesproximal to the edges. This phenomenon is typically referred to asdifferential edge swell. For the purpose of this applicationdifferential edge swell is defined as the edge thickness of awater-swollen OSB panel minus the caliper at a location that is 4 inchesproximal to the edge point:

DIFFERENTIAL EDGE SWELL=(THICKNESS AT PANEL EDGE)−(THICKNESS 4 INCHESPROXIMAL TO THE EDGE)

[0005] There are several factors that effect OSB differential edgeswell. It is helpful to review some of the factors that are believed toeffect differential edge swell.

[0006] Consider a subfloor comprised of OSB panels at a homeconstruction site. Builders are instructed to leave small gaps betweenthe panels in the floor system in order to accommodate linear expansion.During a rainstorm there is a natural tendency for the accumulatedrainwater to flow into these gaps or seams in the floor. Floor joists orprotruding tongues reside directly beneath the seams, thus the waterthat flows into the seams can not readily drain. In this manner theedges of the OSB panels in a wet floor system are exposed to just asmuch water as the major, top-side surfaces of the panels.

[0007] The orientation of the strands in OSB is almost exclusivelyparallel to the plane of the panel. This orientation results inrelatively nonporous major faces and highly porous edges. Thus, theporous edges of OSB panels absorb water faster than do the relativelynonporous major surfaces. An interesting consequence of the anisotropicpore structure of OSB is that brief exposure to water actually producesmaximum differential edge swell. When OSB is subjected to water for arelatively long period of time, the interior regions of the panel havetime to fully hydrate, and swell to become nearly as thick as theperimeter of the panel.

[0008] Most strands in OSB have been compressed to density values thatare significantly greater than that of the virgin wood. Generally, whencompressed wood is exposed to water it springs back to its originaldimensions. Thus, compressed strands will tend to increase in thicknessto at least their original dimensions as they absorb water. Upon drying,the dimensions of these strands do not return to the compressed state.

[0009] Another significant factor, which effects thickness swell in anOSB panel, relates to the wet strength of the strand-to-strand bonds.Strands in an OSB panel are held together with adhesives, such asphenol/formaldehyde (PF) resins or methylene-diphenyldiisocyanate (MDI).As adjacent strands in an OSB panel undergo dramatic dimensional change,there are considerable stresses placed on the strand-to-strand bonds.Some of the water that penetrates an OSB panel can absorb into theadhesive glue-lines and weaken them. Phenolic glue-lines can beespecially susceptible to water absorption. The combination of physicalstresses and low wet strength causes a number of these strand-to-strandbonds to rupture. In many cases, strands in the panel are bent over eachother like a loaded catapult. As bonds rupture, strands are able torelax into a more linear shape, which increases the thickness of thepanel. This part of the thickness swelling process is also notreversible with drying. It should be noted that strand-to-strand bondsnear the edges of the panel will have fewer neighboring strands for loadsharing as compared to strand-to-strand bonds in the interior region ofthe panel. Thus, more strand-to-strand bonds would be expected torupture at the edge of a panel than in the interior regions of thepanel.

[0010] In summary, excessive thickness swell, and especially, excessivedifferential edge swell in OSB panels are facilitated by (1) the seamsin a floor system that trap rainwater against the edges of OSB panels;(2) the relatively porous nature of the OSB edges; (3) the compressedstate of strands in OSB; and (4) the residual stresses in flexed strandsand the rupturing of wet strand-to-strand bonds.

[0011] The consequences of differential edge swell can be significant.When differential edge swell occurs during residential home constructionit manifests itself as ridges along the seams in the subfloor. Buildersare often required to sand the seams in the subfloor in order to removethese ridges and create a flat, smooth subfloor. Obviously, the practiceof sanding the subfloor is costly, time-consuming, and frustrating tothe builder.

[0012] There are available solutions to the problem of differential edgeswell. In wet environments the builder can avoid the differential edgeswell problem by using plywood as the subfloor panel. The thicknessswell associated with plywood when it is subjected to water is usuallyso subtle that sanding is not required. Unfortunately, plywood is moreexpensive than OSB. A desirable panel for the builder to use would beone that is as inexpensive as OSB, but has the thickness swellingproperties of plywood.

[0013] OSB manufacturers have recognized this opportunity for years.Essentially all North American manufacturers of OSB subfloor panelsattempt to improve the dimensional stability of the panel by applying apaint-like formulation to all four edges of the OSB subfloor panel.Subsequent to application this type of formulation dries into ahydrophobic film, which binds strongly to the OSB substrate and inhibitsthe absorption of water into the edge of the panel. Thus, the edgesealant helps to reduce the degree of differential edge swellexperienced by the panel when it is exposed to water during theconstruction process.

[0014] The edge sealant technology is not the only method that can beused by OSB manufacturers to make the panel more resistant todifferential edge swell. Addition of wax to the individual strands makesthem more hydrophobic and significantly decreases the rate at which anOSB panel absorbs water. Apparently, all OSB manufacturers apply wax tothe strands in order to make them more hydrophobic. Unfortunately, theaddition of wax beyond a level of about 1% by weight significantlyinterferes with the strand-to-strand adhesive bonds. Thus, OSBmanufacturers are limited in the amount of wax that can be added to OSBto improve thickness swell.

[0015] It is also known that increasing the amount of bonding resin inthe board can significantly improve the dimensional stability of OSB.Unfortunately, the cost of using higher levels of adhesive issignificantly greater than the cost of applying an edge sealant. Thus,application of an edge sealant is a low-cost method for improving thedimensional stability properties of the OSB.

[0016] There are many patents relating to general sealant compositionsfor wood products. For example U.S. Pat. Nos. 4,722,953; 4,317,755; and4,683,260 all relate to sealants for wood products.

[0017] U.S. Pat. No. 4,897,291 describes a sealant suitable for use onOSB that is primarily composed of water (20-80 weight %), astyrene-butadiene latex with a T_(g) of about −32° C. (2-20 weight %), astyrene-acrylic latex with a T_(g) of about 20° C. (0-15%), a waxhydrophobic filler (3-25 weight %), and a water-soluble methylsiliconate (0.03-1.5 weight %). A preferred hydrophobic filler wasparaffin wax, and a preferred water-soluble methyl siliconate was sodiummethyl siliconate.

[0018] Edge sealants are generally applied to OSB panels at the OSBmill. It is common for liquid, edge sealant formulations to be deliveredin 275-gallon totes to OSB mills in North America. Thus, theseformulations must be stable and resistant to settling or any other typeof gross phase separation during shipping and storage. Stored edgesealant is typically transferred out of the totes through hoses by useof pumps. Filters are placed in the hose line in order to remove anycoarse particles in the edge sealant. The filtered edge sealant is thentransferred to an array of reciprocating spray applicators inside of abooth. Stacks of panels, known as units, are transported into the boothand sprayed on the four vertical sides with edge sealant. The top andbottom major faces of the panels are not sprayed. Successfulformulations dry shortly after application to the panels without the useof heating or ventilation equipment. The fresh coat of edge sealant onunits of OSB must be compatible with water-based stencil paint that isused to label the OSB units. Thus, the drying time of the formulationmust be relatively fast. However, an attempt is made to collect andrecycle sprayed formulation that has missed the panel. Therefore, theformulation must dry sufficiently slowly to be recyclable in the spraybooth collection system.

[0019] Sprayed edge sealant that is not transferred onto the OSB isknown as overspray. Amazingly, overspray can represent over 50% of theprocessed edge sealant. There are several significant problemsassociated with overspray. Generally, the spray booths are open at thefront and back ends in order to allow OSB units to flow into and out ofthe booth. It is common for edge sealant overspray to escape out of thebooth through these entrance and exit points. Conventional, commercialedge sealants have a low viscosity and readily atomize in sprayequipment into fine droplets. These fine droplets can remain airbornefor substantial periods of time outside of the spray booth and representsome level of respiratory hazard to employees working in the plant. Theoverspray that is contained within the booth has a tendency toaccumulate on nozzles, walls, and air filters as well as the floor.Thus, once every two or three days, the spray booth must be shut downfor cleaning. Of course, the overspray also represents a significantmaterial loss at the plant which creates a financial hardship. Existingsuppliers of OSB edge sealant have been repeatedly requested to increasethe viscosity values of their edge sealants, but have not done so.

[0020] Most edge sealant formulations are colored and are applied at alevel that imparts a solid, uniform, attractive appearance to the OSBunit, which helps to promote sales and marketing efforts.Simultaneously, the formulation must not be applied at a level that istoo high. When this occurs, adjacent panels become bonded together inthe stack as the formulation dries. These process constraints oftenforce OSB manufacturers to apply the sealant formulation at a level ofabout 25-45 lb/Msqft of edge surface.

[0021] After a sealant formulation has been applied to the edges of anOSB panel and dried it must reduce the thickness swelling that typicallyoccurs when the panel is exposed to water. Thus, the formulation mustdry to form a film that bonds strongly to the OSB and is relativelyelastic so that it can expand and stretch as the OSB swells. However,the dried edge sealant must not be excessively soft and sticky. Sealededges that are too soft and sticky have been associated with aphenomenon known as tongue-and-groove clicking. Clicking has beenobserved in homes with tongue-and-grooved subfloors. A floor flexes as ahomeowner walks across it, and this strain causes movement in thetongue-and-groove seams. A clicking sound can be observed as sticky edgesealant on the surface of the tongue retracts from sticky edge sealanton the groove wall. Unfortunately, subfloor replacement is the onlyknown remedy for a clicking tongue-and-groove seam.

[0022] It is also important for the dried edge sealant to be resistantto color crocking. For instance, it is not acceptable for a sealed,colored edge sealant to transfer onto an installers hands during theinstallation process. There exists a need for a liquid edge sealantformulation suitable for use in a conventional OSB mill having thefollowing properties and characteristics:

[0023] (1) the formulation exhibits no phase separation or settling forstorage periods of at least three months at ambient conditions;

[0024] (2) the formulation has a viscosity value, which is sufficientlylow for pumping, filtering, and spraying, but is high enough to minimizeoverspray and excessively fine droplet formation in the spray booth;

[0025] (3) the formulation dries quickly subsequent to panelapplication, but overspray dries slowly;

[0026] (4) the formulation is water-based, but it dries to yield a filmthat is highly water repellent and significantly improves thedimensional stability of wet OSB;

[0027] (5) the formulation dries to yield an intensely colored,attractive coating on the edge of the OSB unit at an application rate ofabout 25-45 lb/Msqft, but the colored coating does not transfer onto aninstaller's hands during the installation process; and

[0028] (6) the formulation adheres strongly to the edge of the OSB as itdries into a film and the film is sufficiently elastic to expand withoutcracking as the OSB swells, however, the film is hard enough to avoidthe tongue-and-groove clicking phenomenon.

[0029] A number of these requirements appear to represent physicalproperty contradictions. The present invention seeks to fulfill theseneeds and provides further related advantages.

SUMMARY OF THE INVENTION

[0030] In one aspect, the present invention provides a formulation forsealing the edge of a wood-based panel. The formulation includes abutylacrylate latex, a solution of a wax in oil, a surfactant, andwater.

[0031] In another aspect of the invention, a wood-based panel that isedge-sealed with a sealant formulation is provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0032] In one aspect, the present invention provides a stable,single-component liquid formulation that can be sprayed onto the edge ofOSB panels at a wet spread rate of about 25-50 lb/Msqft and dried toyield a coating which substantially retards the rate of edge thicknessswell and thereby reduces differential edge swell. The formulationincludes water (20-60% by weight); a butylacrylate latex (10-25% byweight); a solution (10-30% by weight) of a wax in oil; and a surfactant(1-5% by weight) based on salts of long-chain organic acids. Otheradditives can be included in the formulation such as viscosifyingagents, additional emulsifying agents, dispersing aids, colorants,opacifying agents, preservatives, a second latex, coalescing agents, andOSB adhesive wet-strength enhancing agents.

[0033] Suitable butylacrylate lattices can be based on copolymers ofbutylacrylate and styrene or butylacrylate and methacrylate. The latexis preferably stable in a pH range of 7-9. Films cast from the neatlatex at a temperature of 20° C. preferably have a T_(g) of −30° to 0°C. and an ultimate elongation of 1000 to 3000%. The films must exhibit0-1% swell upon soaking in water at a temperature of 20° C. for 48 h. Apreferred butylacrylate latex is known as AcryGen 4096D and is producedby GenCorp Performance Chemicals [Fitchburg, Mass.].

[0034] A second latex can be incorporated into the formulation withbeneficial results. The latex is preferably stable in a pH range of 7-9.Films cast from the neat latex at a temperature of 20° C. preferablyhave a T_(g) of 20-40° C. The films exhibit 0-1% swell upon soaking inwater at a temperature of 20° C. for 48 h. A preferred second latex isknown as Rhoplex CS4000 and is produced by the Rohm and Haas Company[Philadelphia, Pa.]. Use of this second latex significantly reduces thedegree of tack in the edge sealant, and thus helps to reduce the risk oftongue-and-grooved clicking in the field. Higher levels of the first andsecond latex substantially reduces the risk of color crocking in thefield.

[0035] The solution of wax in oil consists of a hydrophobic wax (10-80%by weight) with a melting point in the range of 30-70° C. and ahydrophobic oil (20-90% by weight) with a melting point that is lessthan 20° C. The melting point of the mixture should be in the range of25-70° C. Suitable waxes include paraffin wax, scale wax, slack wax,lanolin and hydrogenated soybean oil. Suitable oils include soybean oil,sunflower oil, castor oil, rapeseed oil, safflower oil, corn oil,linseed oil, tung oil, and 1-octadecene. It is important that thesolution of wax in oil have a freezing point that is in the range of30-60° C., while a freezing point in the range of 35-45° C. ispreferred. A preferred solution of wax in oil is comprised of soybeanoil (40-70% by weight) and paraffin wax (60-30% by weight).

[0036] The surfactant based on salts of long-chain organic acids can beprepared from bases, such as morpholine, triethanolamine, ammonia, andsodium carbonate; and long chain organic acids, such as stearic acid,palmitic acid, myristic acid, and lauric acid. A preferred surfactant isa salt based on morpholine and a mixture stearic and palmitic acids. Theratio of base to organic acid should be balanced on a molar basis. Theamount of surfactant used had a significant effect on the stability ofthe formulation. Excessive amounts of surfactant can result in a frothyformulation and poor differential edge swell value of OSB treated withthe sealant.

[0037] Viscosifying agents are exemplified by relatively non-ionicpolysaccharides such as carboxymethylcellulose or hydroxyethylcellulose.A preferred viscosifying agent is known as Natrosol 250 MBRhydroxyethylcellulose and is produced by Hercules, Incorporated[Wilmington, Del.]. Higher levels of viscosifying agent can be used toreduce overspray without adversely effecting the differential edge swellvalues for OSB treated with said sealant.

[0038] Emulsifying agents are generally based on long chain aliphaticcompounds with alcohol and/or ester functionality. A preferredemulsifying agent is stearyl alcohol. The emulsifying agent can be usedto improve the stability of the formulation. Excessive levels ofemulsifying agent can result in unacceptably high viscosity values andpoor differential edge swell values for OSB treated with said sealant.

[0039] Dispersing aids can be beneficial for use in conjunction withpigments or powders. A preferred dispersing aid is known as Surfynol104PA and is produced by the Air Products and Chemical Corporation[Allentown, Pa.].

[0040] Colorants that are most suitable for this invention includewater-based pigment dispersions, such as those manufactured by the SunChemical Corporation [Amelia, Ohio.], and oil-based pigment dispersions,such as those produced by the Harwick Chemical Manufacturing Corporation[Cuyahoga Falls, Ohio.].

[0041] Opacifying agents are exemplified by titanium dioxide powder suchas that known as Tronox CR-826 and produced by the Kerr-McGee ChemicalCorporation [Oklahoma City, Okla.].

[0042] A suitable preservative for the formulation is known as Dowicil75 and is produced by DOW Incorporated [Midland, Mich.].

[0043] A suitable coalescing agent for the formulation is known asTexanol and is produced by the Eastman Chemical Company [Kingsport,Tenn.].

[0044] The OSB adhesive wet strength agents are compounds that caninteract with the OSB adhesive at the edge of the OSB panel in a mannerthat increases the wet strength of the strand-to-strand bonds. Oneexample of such an agent is sodium borate, which is able to complex withpartially cured phenolic resins and drastically reduces the propensityof the resin to hydrate. Sodium borate salts are conveniently preparedby combining aqueous solutions of boric acid and sodium hydroxide. Theuse of the sodium borate additive significantly decreases thedifferential edge swell values of OSB bonded with PF resin and treatedwith said sealant. Excessive levels of the sodium borate in theformulation does result in phase separation.

[0045] In one embodiment, the edge sealant formulation includes water(25-60% by weight); a viscosifying agent (0.1-0.8% by weight); abutylacrylate latex (10-25% by weight); an acrylic latex (10-25% byweight); an alkali borate salt (0.5-1.0% by weight); a water-solublebase (0.5-1.0% by weight); a preservative (0.01-0.1% by weight), adispersing agent (0.01-0.1% by weight), an opacifying agent (0.1 - 1.0%by weight), colorants (1.0-15.0% by weight); and wax (5.0-15% byweight), oil (5.0-15% by weight), emulsifying agent (0.1-1.0% byweight), and a long chain organic acid (1.0-4.0% by weight).

[0046] In another embodiment, the edge sealant formulation includeswater (45-55% by weight); a viscosifying agent (0.3-0.6% by weight); abutylacrylate latex (12-15% by weight); an acrylic latex (12-15% byweight); an alkali borate salt (0.8-1.0% by weight); a water-solublebase (0.5-0.8% by weight); a preservative (0.01-0.04% by weight), adispersing agent (0.01-0.05% by weight), an opacifying agent (0.6-0.8%by weight), colorants (10-15% by weight); and wax (8.0-10% by weight),oil (10-13% by weight), emulsifying agent (0.6-1.0% by weight), and along chain organic acid (3.0-4.0% by weight).

[0047] The following examples are provided to illustrate, not limit, theinvention.

EXAMPLES Example 1

[0048] A representative edge sealant formulation was prepared by thefollowing procedure. A 1 L Waring blender was charged with warm water(55° C.; 378.8 g) and a hydroxyethylcellulose powder (4.0 g), known asNatrosol 250MBR from Hercules Incorporated [Wilmington, Del.]. Themixture was stirred at the highest rate of shear for 30 s. An aqueous30% ammonium hydroxide solution (4.0 g) was then added to the blenderand the contents were stirred at the highest rate of shear for 30 s. Apreservative (0.4 g), known as Dowicil 75 from Dow Chemical Incorporated[Midland, Mich.] was then added to the blender and the contents werestirred at the lowest rate of shear for 30 s. A dispersing aid (1.0 g)comprised of an acetylenic diol in isopropyl alcohol, known as Surfynol104PA from Air Products and Chemicals, Incorporated [Allentown, Pa.] wasthen added to the blender and the contents were stirred at the lowestrate of shear for 15 s. Titanium dioxide (5.0 g), known as Tronox CR-822from the Kerr-McGee Chemical Corporation [Oklahoma City, Okla.], wasthen added to the blender and the contents were stirred at the highestrate of shear for 90 s. A butylacrylate/styrene polymer latex (15.0 g)with a T_(g) of −13° C. and a percent solids level of 45%, known asAcryGen 4660, which is produced by GenCorp Performance Chemicals[Fitchburg, Mass.], was then added to the blender and the contents werestirred at the lowest rate of shear for 30 s. A hot, fresh solution (80°C.; 180.0 g) of paraffin wax (80.0 parts by weight), known as IGI 1230from the International Group, Incorporated [Wayne, Pa.], and thermallymodified linseed oil (160.0 parts by weight) known as Archer-1 from theArcher Daniels Midland Company [Redwing, Minn.], was then added to theblender and the contents were stirred at the highest rate of shear for90 s. An aqueous #12 21090 diarylide yellow pigment dispersion (11.3 g),known as Sunsperse YFD 2193 from the Sun Chemical Corporation [Amelia,Ohio.] was then added to the blender and the contents were stirred atthe highest rate of shear for 30 s. An aqueous #15:3 74160 phthalo bluepigment dispersion (2.7 g), known as Sunsperse BHD 6000 from the SunChemical Corporation [Amelia, Ohio.] was then added to the blender andthe contents were stirred at the highest rate of shear for 30 s.Ethylene glycol monobutylether (10.0 g) from Dow Chemical Incorporated[Midland, Mich.] was then added to the blender and the contents werestirred at the lowest rate of shear for 30 s. A butylacrylate/styrenepolymer latex (387.8 g) with a T_(g) of −11° C. and a percent solidslevel of 50%, known as AcryGen 4096D, which is produced by GenCorpPerformance Chemicals [Fitchburg, Mass.], was then added to the blenderand the contents were stirred at the lowest rate of shear for 30 s.

[0049] The resulting liquid formulation was then transferred into aclosed plastic container, which was stored at a temperature of 20° C.When the temperature of the formulation had decreased to 20-25° C., theviscosity of the formulation was measured by use of an Electronic ThomasStormer Viscometer by the Cannon Instrument Company of State College,Pa. and was found to be about 58 KU. The percent solids value of theformulation was about 40%. When the formulation was applied to a woodensubstrate it dried into a coating that had a green color that wassimilar to the green color of a dried film from the aforementioned PF6014-13 sealant formulation (Associated Chemist Incorporated). The driedcoating was highly elastic and sticky to the touch.

[0050] Application of Formulation to OSB Panels. Two OSB subfloor panelsthat were manufactured at the Weyerhaeuser OSB mill located in Edson,AB, Canada during the summer months of 1997 were obtained and the outer6 inches of each panel was removed by use of a saw. The remaininginterior portions of the panels were cut into square-shaped sections(12×12 inches) (60 count). The total group of sections was randomizedthoroughly and two subgroups of ten sections each were isolated. One ofthese subgroups was not treated and was designated as a control group.The control group samples were immediately transferred into anenvironmental chamber (50% R.H., 20° C.) where they were stacked in analternating configuration with spacers and allowed to equilibrate for aperiod of 14 h prior to testing. The second subgroup of sections,designated as the Weyerhaeuser group, was spray coated with the liquidedge sealant described. in this example on the section edges at a spreadrate of 43 wet lb per Msqft. These samples were stacked in analternating configuration with spacers and immediately transferred intoan environmental chamber (50% R.H., 20° C.) where the coating dried fora period of 14 h prior to testing. These samples were subjected to thefollowing edge swell test.

[0051] Two-Day Soak Test. Initial caliper measurements were made on eachedge of each sample at the midpoint. Caliper measurements were also madeat midpoint locations proximal from each edge by 4.0 inches. Each pointof caliper measurement was marked with a pen so that subsequentmeasurements could be made at exactly the same location. The calipermeasurements were made by use of a Mitutoyo Digimatic Indicator[#543-525A] which was mounted to a base with a circular foot (1.0 inchin diameter) and circular top (1.0 inch in diameter) from the B.C. AmesCo.; Waltham, Mass. The signal from these measurements was sent directlyto an IBM computer and stored in a series of data files which was thenimported into an EXCEL program.

[0052] Each sample was placed in a continuous water soak testingapparatus. The panel sections were secured 1.0 inch beneath the waterline by use of metal pipes, which spanned across the surface of thetank. Tap water was preheated to a temperature of 72 F. and was pumpedinto the front end of the tank at a flow rate of about 10 gallons perhour. An open pipe, which was installed at the back end of the tank andwas connected to a drain was positioned at a height within the tank sothat the water line was always 1.0 inch above the top of the panelsections. The excess water was removed via this drain pipe.

[0053] After 24 h of soaking, each of the samples was removed from thebath and was measured for caliper at each of the previously measuredlocations. These caliper measurements were conducted within 2 h ofremoving the samples from the bath. The samples were then immediatelyreturned to the soak tank.

[0054] At the 48 h point, the samples were once again removed from thetank and measured for caliper at each of the previously measuredlocations. These measurements were conducted within 2 h of removing thesamples from the water.

[0055] Each sample was then dried for 24 h in a forced air oven whichwas set at a temperature of 83° C. A final set of caliper measurementswas made on each panel section within 2 h of removing them from theoven.

[0056] Calculations: The following values were calculated for each edgeof each sample for each point in time of the experiment.

[0057] Percent Thickness Swell: % edge thickness swell=[(edge caliper attime t)/(initial edge caliper)]×100%

[0058] % 4 inches thickness swell=[(4 inches caliper at time t)/(initial4 inches caliper)]×100%

[0059] Differential Edge Swell: DES (4 inches)=(edge caliper at timet)−(4 inches caliper at time t)

[0060] A separate set of calculations was performed for each day of theexperiment (e.g., day 0, 1, 2, and 3).

[0061] Average swell values for each section (1 foot×1 foot) werecalculated by averaging the four values associated with each edge in thesample. These averaged values were assumed to represent an ‘n’ of onefor statistical calculations. Thus, the ‘n’ of each group was assumed tobe 10.

[0062] The average values and standard deviation values for eachparameter in each group were calculated. The average values associatedwith different edge treatments were compared based on a differencebetween two means two-tailed students “t” test [A.S.C. Ehrenberg, DataReduction: Analysing and Interpreting Statistical Data, 302-304, JohnWiley & Sons, New York, N.Y. (1978)]. These results are shown in Tables1 and 2. TABLE 1 Example 1 percent thickness swell values at sampleedges. THICKNESS SWELL THICKNESS SWELL CONDITIONING OF CONTROL OFWEYERHAEUSER TIME (DAYS) GROUP SEALANT GROUP 0 0 0 1 13.3^(a) (1.2) 9.0^(b) (0.8) 2 17.0^(a) (1.2) 13.3^(b) (0.8) 3 (redry) 10.0^(a) (1.0) 7.3^(b) (0.7)

[0063] TABLE 2 Example 2 differential edge swell values (mils).DIFFERENTIAL EDGE CON- DIFFERENTIAL EDGE SWELL OF DITIONING SWELL OFCONTROL WEYERHAEUSER TIME (DAYS) GROUP SEALANT GROUP 0  6^(a) (0)  7^(b)(1) 1 58^(a) (8) 31^(b) (7) 2  65^(a) (10) 43^(b) (9) 3 (redry) 34^(a)(8) 19^(b) (8)

[0064] Note: numbers in parenthesis are standard deviation values. Thosedifferential edge swell values in a row that do not share a commonsuperscript are significantly (p<0.05) distinct at a 95% confidenceinterval.

Example 2

[0065] A representative edge sealant was prepared by the followingprocedure. A 1 L Waring blender was charged with hot water (70° C.;356.0 g) and a hydroxyethylcellulose powder (3.0 g), known as Natrosol250MBR from Hercules Incorporated Aqualon Division [Wilmington, Del.].The mixture was stirred at the highest rate of shear for 30 s. Anaqueous 50% morpholine solution (6.0 g) was then added to the blenderand the contents were stirred at the highest rate of shear for 30 s. Apreservative (0.4 g), known as Dowicil 75 from Dow Chemical Incorporated[Midland, Mich.] was then added to the blender and the contents werestirred at the lowest rate of shear for 30 s. A dispersing aid (0.5 g)comprised of an acetylenic diol in isopropyl alcohol, known as Surfynol104PA from Air Products and Chemicals, Incorporated [Allentown, Pa.] wasthen added to the blender and the contents were stirred at the lowestrate of shear for 15 s. Titanium dioxide (3.5 g), known as Tronox CR-822from the Kerr-McGee Chemical Corporation [Oklahoma City, Okla.], wasthen added to the blender and the contents were stirred at the highestrate of shear for 90 s. An aqueous #12 21090 diarylide yellow pigmentdispersion (13.6 g), known as Sunsperse YFD 2193 from the Sun ChemicalCorporation [Amelia, Ohio.] was then added to the blender and thecontents were stirred at the highest rate of shear for 30 s. An aqueous# 15:3 74160 phthalo blue pigment dispersion (3.0 g), known as SunsperseBHD 6000 from the Sun Chemical Corporation [Amelia, Ohio.] was thenadded to the blender and the contents were stirred at the highest rateof shear for 30 s. A green oil-based pigment dispersion (12.0 g), knownas Stan-Tone HCC 25012 from the Harwick Chemical ManufacturingCorporation [Cuyahoga Falls, Ohio.] was then added to the blender andthe contents were stirred at the highest rate of shear for 90 s. A hot,fresh solution (80° C.; 233.0 g) of paraffin wax (122.0 g), known as IGI1230 from the International Group, Incorporated [Wayne, Pa.], soybeanoil (125.0 g) from the Archer Daniels Midland Company [Redwing, Minn.],1-octadecanol (3.0 g), and a mixture of long-chain carboxylic acids (92%stearic acid and palmitic acid) (50.0 g) known as Pristerene 4910 fromUniquema [Chicago, Ill.] was then added to the blender and the contentswere stirred at the highest rate of shear for 90 s. Abutylacrylate/styrene polymer latex (150.0 g) with a T_(g) of −11° C.and a percent solids level of 50%, known as AcryGen 4096D from GenCorpPerformance Chemicals [Fitchburg, Mass.], was then added to the blenderand the contents were stirred at the lowest rate of shear for 30 s. Anacrylic polymer latex (135.0 g) with a T_(g) of 32° C. and a percentsolids level of 48%, known as Rhoplex CS-4000 from the Rohm and HaasCompany [Philadelphia, Pa.], was then added to the blender and thecontents were stirred at the lowest rate of shear for 30 s. Water (84.0g) was then added to the blender and the contents were stirred at thelowest rate of shear for 30 s.

[0066] The resulting liquid formulation was then transferred into aclosed plastic container, which was stored at a temperature of 20° C.When the temperature of the formulation had decreased to 20-25° C. theviscosity of the formulation was measured by use of a Brookfieldviscometer. The percent solids value of the formulation was measured andfound to be about 40%. When the formulation was applied to a woodensubstrate it dried into a coating that had a green color that wassimilar to the green color of a dried film from the aforementioned PF6014-13 sealant formulation (Associated Chemist Incorporated). The driedcoating was highly elastic and slightly tacky.

Application of Formulation to OSB Panels

[0067] Three OSB subfloor panels that were manufactured at theWeyerhaeuser OSB mill located in Edson, AB, Canada during the fallmonths of 1999 were obtained and the outer 6 inches of each panel wereremoved by use of a saw. The remaining interior portions of the panelswere cut into square shaped sections (12 inches×12 inches) (90 count).The total group of sections was randomized thoroughly and six subgroupsof ten sections each were isolated. One of these subgroups was nottreated and was designated as a control group.

[0068] The control group samples were immediately transferred into anenvironmental chamber (50% R.H., 20° C.) where they were stacked in analternating configuration with spacers and allowed to equilibrate for aperiod of 14 h prior to testing.

[0069] The second group of sections was stacked and the edges of thestack were spray coated with the liquid edge sealant described in thisexample at a spread rate of 43 wet lb per Msqft.

[0070] The third, fourth and fifth groups were each stacked and spraycoated on the edges with commercially available OSB edge sealants at aspread rate of 43 wet lb per Msqft. All coated samples were then stackedin an alternating configuration with spacers and immediately transferredinto an environmental chamber (50% R.H., 20° C.) where the coatingsdried for a period of 14 h prior to testing. These samples were thensubjected to the edge swell test described in Example 1. TABLE 3 Example2 Brookfield ciscosity* values of OSB edge sealants. EDGE SEALANTFORMULATION VISCOSITY (cps) Weyerhaeuser Example 2 8780 AssociatedChemists, Inc. PF6014-13 2600 Socete Laurentide Inc. 474-280 4060 TheReynolds Company 100-47 3150

[0071] TABLE 4 Example 2 percent thickness swell values at sample edges.CONDITIONING Associated Societe TIME Control Weyerhaeuser Chemists Inc.Laurentide Inc. The Reynolds (DAYS) No sealant Example 2 PF6014-13474-280 Co. 100-47 0 0 0 0 0 0 1 11.8^(a) 8.53^(b) (0.69) 8.24^(b)(1.17)  9.58^(c) (0.75) 9.59^(c) (1.11) (0.86) 2 15.0^(a) 12.3^(b)(0.76) 11.8^(b) (0.95) 13.0^(bc) (0.82) 13.3^(c) (1.15) 3 (redry)7.93^(a) 6.36^(b) (0.92) 6.13^(b) (0.77)  7.14^(c) (0.61) 7.15^(c)(0.70) (0.68)

[0072] TABLE 5 Example 2 differential edge swell values (mils).Associated Science CONDITIONING Control Weyerhaeuser Chemists Inc.Laurentide Inc. The Reynolds TIME (DAYS) No sealant Example 2 PF6014-13474-280 Co. 100-47 0  2^(a) (1)  5^(b) (1)  4^(c) (1)  5^(b) (2)  3^(d)(1) 1 47^(a) (6) 26^(bd) (5) 23^(b) (7) 33^(c) (6) 31^(cd) (6) 2 55^(a)(7) 37^(b) (6) 32^(b) (7) 43^(c) (4) 42^(cd) (8) 3 (redry) 25^(a) (5)14^(b) (6) 14^(b) (7) 21^(c) (3) 20^(c) (5)

[0073] Note: numbers in parenthesis are standard deviation values. Thosedifferential edge swell values in a row that do not share a commonsuperscript are significantly (p<0.05) distinct at a 95% confidenceinterval.

Example 3

[0074] Two representative edge sealant formulations were prepared by thefollowing procedures.

[0075] Sealant 3A. A 2 gallon blender equipped with an Arde Barincorotor stator (down mode) was charged with hot water (70° C.; 2252.0 g)and a hydroxyethylcellulose powder (22.0 g), known as Natrosol 250MBRfrom Hercules Incorporated Aqualon Division [Wilmington, Del.]. Themixture was agitated for 20 minutes at 50% of maximum power. An aqueous50% morpholine solution (36.0 g) was then added to the blender and thecontents were agitated for 5 minutes at 50% of maximum power. Apreservative (2.4 g), known as Dowicil 75 from Dow Chemical Incorporated[Midland, Mich.] was then added to the blender and the contents wereagitated for 5 minutes at 50% of maximum power. A dispersing aid (3.0 g)comprised of an acetylenic diol in isopropyl alcohol, known as Surfynol104PA from Air Products and Chemicals, Incorporated [Allentown, Pa.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. Titanium dioxide (21.0 g), known as TronoxCR-826 from the Kerr-McGee Chemical Corporation [Oklahoma City, Okla.],was then added to the blender and the contents were agitated for 10minutes at 50% of maximum power. An aqueous #12 21090 diarylide yellowpigment dispersion (73.2 g), known as Sunsperse YFD 2193 from the SunChemical Corporation [Amelia, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. Anaqueous #15:3 74160 phthalo blue pigment dispersion (14.4 g), known asSunsperse BHD 6000 from the Sun Chemical Corporation [Amelia, Ohio.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. A green oil-based pigment dispersion (36.0 g),known as Stan-Tone HCC 25012 from the Harwick Chemical ManufacturingCorporation [Cuyahoga Falls, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. A hot,fresh solution (80° C.; 1500.0 g) of paraffin wax (844.0 g), known asIGI 1230 from the International Group, Incorporated [Wayne, Pa.],soybean oil (750.0 g) from the Archer Daniels Midland Company [Redwing,Minn.], 1-octadecanol (6.0 g), and a mixture of long-chain carboxylicacids (92% stearic acid and palmitic acid) (200.0 g) known as Pristerene4910 from Uniquema [Chicago, Ill.] was then added to the blender and thecontents were agitated for 20 minutes at 50% of maximum power. Abutylacrylate/styrene polymer latex (750.0 g) with a T_(g) of −11° C.and a percent solids level of 50%, known as AcryGen 4096D from GenCorpPerformance Chemicals [Fitchburg, Mass.], was then added to the blenderand the contents were agitated for 5 minutes at 30% of maximum power. Anacrylic polymer latex (750.0 g) with a T_(g) of 32° C. and a percentsolids level of 48%, known as Rhoplex CS-4000 from the Rohm and HaasCompany [Philadelphia, Pa.], was then added to the blender and thecontents were agitated for 5 minutes at 30% of maximum power. Water(540.0 g) was then added to the blender and the contents were agitatedfor 5 minutes at 30% of maximum power.

[0076] The resulting liquid formulation was then transferred into aclosed plastic container, which was stored at a temperature of 20° C.The percent solids value of the formulation was measured and found to beabout 40%. When the formulation was applied to a wooden substrate itdried into a coating that had a green color that was similar to thegreen color of a dried film from the aforementioned PF 6014-13 sealantformulation (Associated Chemist Incorporated). The dried coating washighly elastic and slightly tacky.

[0077] Sealant 3B. A 2 gallon blender equipped with an Arde Barincorotor stator (down mode) was charged with hot water (70° C.; 2249.0 g)and a hydroxyethyl-cellulose powder (25.0 g), known as Natrosol 250MBRfrom Hercules Incorporated Aqualon Division [Wilmington, Del.]. Themixture was agitated for 20 minutes at 50% of maximum power. An aqueous50% morpholine solution (36.0 g) was then added to the blender and thecontents were agitated for 5 minutes at 50% of maximum power. Apreservative (2.4 g), known as Dowicil 75 from Dow Chemical Incorporated[Midland, Mich.] was then added to the blender and the contents wereagitated for 5 minutes at 50% of maximum power. A dispersing aid (3.0 g)comprised of an acetylenic diol in isopropyl alcohol, known as Surfynol104PA from Air Products and Chemicals, Incorporated [Allentown, Pa.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. Titanium dioxide (21.0 g), known as TronoxCR-826 from the Kerr-McGee Chemical Corporation [Oklahoma City, Okal.],was then added to the blender and the contents were agitated for 10minutes at 50% of maximum power. An aqueous #12 21090 diarylide yellowpigment dispersion (73.2 g), known as Sunsperse YFD 2193 from the SunChemical Corporation [Amelia, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. Anaqueous #15:3 74160 phthalo blue pigment dispersion (14.4 g), known asSunsperse BHD 6000 from the Sun Chemical Corporation [Amelia, Ohio.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. A green oil-based pigment dispersion (36.0 g),known as Stan-Tone HCC 25012 from the Harwick Chemical ManufacturingCorporation [Cuyahoga Falls, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. A hot,fresh solution (80° C.; 1500.0 ) of paraffin wax (844.0 g), known as IGI1230 from the International Group, Incorporated [Wayne, Pa.], soybeanoil (750.0 g) from the Archer Daniels Midland Company [Redwing, Minn.],1-octadecanol (6.0 g), and a mixture of long-chain carboxylic acids (92%stearic acid and palmitic acid) (200.0 g) known as Pristerene 4910 fromUniquema [Chicago, Ill.] was then added to the blender and the contentswere agitated for 20 minutes at 50% of maximum power. A solution (540.0g) of water (856.0 g), boric acid (64.0 g) and 50% sodium hydroxide(80.0 g) was then added to the blender and the contents were agitatedfor 5 minutes at 30% of maximum power. A butylacrylate/styrene polymerlatex (750.0 g) with a T_(g) of −11° C. and a percent solids level of50%, known as AcryGen 4096D from GenCorp Performance Chemicals[Fitchburg, Mass.], was then added to the blender and the contents wereagitated for 5 minutes at 30% of maximum power. An acrylic polymer latex(750.0 g) with a T_(g) of 32° C. and a percent solids level of 48%,known as Rhoplex CS-4000 from the Rohm and Haas Company [Philadelphia,Pa.], was then added to the blender and the contents were agitated for 5minutes at 30% of maximum power.

[0078] The resulting liquid formulation was then transferred into aclosed plastic container, which was stored at a temperature of 20° C.The percent solids value of the formulation was measured and found to beabout 40%. The formulation was stable in excess of three months at atemperature of 20° C. When the formulation was applied to a woodensubstrate it dried into a coating that had a green color that wassimilar to the green color of a dried film from the aforementioned PF6014-13 sealant formulation (Associated Chemist Incorporated). The driedcoating was highly elastic and slightly tacky.

[0079] Application of Formulations to OSB Panels. Two OSB subfloorpanels that were manufactured at the Weyerhaeuser OSB mill located inGrayling, Mich. during the fall months of 1999 were obtained and theouter 6 inches of each panel were removed by use of a saw. This OSBcontained a PF resin in both the surface and core layers. The remaininginterior portions of the panels were cut into square shaped sections (12inches×12 inches) (60 count). The total group of sections was randomizedthoroughly and four sub-groups of ten sections each were isolated. Oneof these subgroups was not treated and was designated as a controlgroup.

[0080] The control group samples were immediately transferred into anenvironmental chamber (50% R.H., 20° C.) where they were stacked in analternating configuration with spacers and allowed to equilibrate for aperiod of 14 h prior to testing.

[0081] A second group of sections was stacked and the edges of the stackwere spray coated with the liquid edge sealant described in this exampleand labeled as ‘3A’ at a spread rate of 43 wet lb per Msqft.

[0082] A third group of sections was stacked and the edges of the stackwere spray coated with the liquid edge sealant described in this exampleand labeled as ‘3B’ at a spread rate of 43 wet lb per Msqft.

[0083] A fourth group of sections was stacked and the edges of the stackwere spray coated with a liquid edge sealant known as PF6014-13 fromAssociated Chemists Inc. at a spread rate of 43 wet lb per Msqft.

[0084] All coated samples were then stacked in an alternatingconfiguration with spacers and immediately transferred into anenvironmental chamber (50% R.H., 20° C.) where the coatings dried for aperiod of 14 h prior to testing. These samples were then subjected tothe edge swell test described in Example 1. TABLE 6 Example 3 percentthickness swell values at sample edges (Grayling OSB). AssociatedCONDITIONING Control Weyerhaeuser Weyerhaeuser Chemists TIME (DAYS) Nosealant Example 3A Example 3B Inc. PF6014-13 0 0 0 0 0 1 12.3^(a) (0.90)10.3^(b) (1.50) 8.84^(c) (1.11) 9.03^(c) (0.65) 2 17.0^(a) (1.36)14.6^(bc) (1.36) 13.6^(b) (1.57) 14.9^(c) (0.81) 3 (redry) 11.2^(a)(1.38) 9.23^(b) (1.40) 8.54^(b) (1.42) 10.7^(a) (0.97)

[0085] TABLE 7 Example 3 differential edge swell values (mils) (GraylingOSB). Associated CONDITIONING Control Weyerhaeuser Weyerhaeuser ChemistsTIME (DAYS) No sealant Example 3A Example 3B Inc. PF6014-13 0 1^(a) (1) 2^(ab) (2) 3^(b) (2)  2^(ab) (2) 1 49^(a) (7)  32^(b) (9) 23^(c) (10)23^(c) (4) 2 62^(a) (11) 43^(b) (8) 38^(b) (13) 43^(b) (5) 3 (redry)48^(a) (11) 32^(bc) (8) 28^(b) (13) 39^(ac) (7)

Example 4

[0086] A representative edge sealant formulation was prepared by thefollowing procedure. A 2 gallon blender equipped with an Arde Barincorotor stator (down mode) was charged with hot water (70° C.; 2664.6 g)and a hydroxyethylcellulose powder (19.0 g), known as Natrosol 250MBRfrom Hercules Incorporated Aqualon Division [Wilmington, Del.]. Themixture was agitated for 20 minutes at 50% of maximum power. An aqueous50% morpholine solution (36.0 g) was then added to the blender and thecontents were agitated for 5 minutes at 50% of maximum power. Apreservative (2.4 g), known as Dowicil 75 from Dow Chemical Incorporated[Midland, Minn.] was then added to the blender and the contents wereagitated for 5 minutes at 50% of maximum power. A dispersing aid (3.0 g)comprised of an acetylenic diol in isopropyl alcohol, known as Surfynol104PA from Air Products and Chemicals, Incorporated [Allentown, Pa.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. Titanium dioxide (20.0 g), known as TronoxCR-826 from the Kerr-McGee Chemical Corporation [Oklahoma City, Okal.],was then added to the blender and the contents were agitated for 10minutes at 50% of maximum power. An aqueous #12 21090 diarylide yellowpigment dispersion (66.0 g), known as Sunsperse YFD 2193 from the SunChemical Corporation [Amelia, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. Anaqueous # 15:3 74160 phthalo blue pigment dispersion (13.0 g), known asSunsperse BHD 6000 from the Sun Chemical Corporation [Amelia, Ohio.] wasthen added to the blender and the contents were agitated for 5 minutesat 50% of maximum power. A green oil-based pigment dispersion (33.0 g),known as Stan-Tone HCC 25012 from the Harwick Chemical ManufacturingCorporation [Cuyahoga Falls, Ohio.] was then added to the blender andthe contents were agitated for 5 minutes at 50% of maximum power. A hot,fresh solution (80° C.; 1600.0 g) of paraffin wax (576.0 g), known asIGI 1230 from the International Group, Incorporated [Wayne, Pa.],soybean oil (924.0 g) from the Archer Daniels Midland Company [Redwing,Minn.], hydrogenated soybean oil (60.0 g) known as Natura Shield ASW-220from the Archer Daniels Midland Company [Redwing, Minn.], and a mixtureof long-chain carboxylic acids (92% stearic acid and palmitic acid)(240.0 g) known as Pristerene 4910 from Uniquema [Chicago, Ill.] wasthen added to the blender and the contents were agitated for 20 minutesat 50% of maximum power. A solution (540.0 g) of water (856.0 g), boricacid (64.0 g) and 50% sodium hydroxide (80.0 g) was then added to theblender and the contents were agitated for 5 minutes at 30% of maximumpower. A butylacrylate/styrene polymer latex (550.0 g) with a T_(g) of−11 ° C. and a percent solids level of 50%, known as AcryGen 4096D fromGenCorp Performance Chemicals [Fitchburg, Mass.], was then added to theblender and the contents were agitated for 5 minutes at 30% of maximumpower. An acrylic polymer latex (450.0 g) with a T_(g) of 32° C. and apercent solids level of 48%, known as Rhoplex CS-4000 from the Rohm andHaas Company [Philadelphia, Pa.], was then added to the blender and thecontents were agitated for 5 minutes at 30% of maximum power.

[0087] The resulting liquid formulation was then transferred into aclosed plastic container, which was stored at a temperature of 20° C.The percent solids value of the formulation was measured and found to beabout 38%. The formulation was stable in excess of two months at atemperature of 20° C. When the formulation was applied to a woodensubstrate it dried into a coating that had a green color that wassimilar to the green color of a dried film from the aforementioned PF6014-13 sealant formulation (Associated Chemist Incorporated). The driedcoating was highly elastic and slightly tacky.

[0088] Application of Formulation to OSB Panels. Two OSB subfloor panelsthat were manufactured at the Weyerhaeuser OSB mill located in Edson, ABCanada during the spring months of 2000 were obtained and the outer 6inches of each panel were removed by use of a saw. The remaininginterior portions of the panels were cut into square shaped sections (12inches×12 inches) (60 count). The total group of sections was randomizedthoroughly and four subgroups of ten sections each were isolated. One ofthese subgroups was not treated and was designated as a control group.

[0089] The control group samples were immediately transferred into anenvironmental chamber (50% R.H., 20° C.) where they were stacked in analternating ion with spacers and allowed to equilibrate for a period of14 h prior to testing.

[0090] A second and third group of sections were stacked and the edgesof each stack were spray coated with the liquid edge sealant describedin this example at a spread rate of 43 wet lb per Msqft.

[0091] A fourth group of sections was stacked and the edges of the stackwere spray coated with a liquid edge sealant known as PFX99L94A fromAssociated Chemists Inc. at a spread rate of 43 wet lb per Msqft.

[0092] All coated samples were then stacked in an alternatingconfiguration with spacers and immediately transferred into anenvironmental chamber (50% R.H., 20° C. where the coatings dried for aperiod of 14 h prior to testing. These samples were then subjected tothe edge swell test described in Example 1. TABLE 8 Example 4 percentthickness swell values at sample edges (Edson OSB). WeyerhaeuserWeyerhaeuser Associated CONDITIONING Control Example 4 Example 4Chemists TIME (DAYS) No sealant (replicate 1) (replicate 2) Inc.PFX99L94A 0 0 0 0 0 1 12.4^(a) (0.69) 7.83^(b) (0.55) 7.89^(b) (0.80)7.78^(b) (0.74) 2 14.8^(a) (0.77) 11.0^(b) (1.02) 10.6^(b) (1.39)10.9^(b) (1.14) 3 (redry) 7.52^(a) (0.56) 5.20^(b) (0.88) 5.07^(b)(1.43) 5.61^(b) (0.85)

[0093] TABLE 9 Example 4 differential edge swell values (mils) (EdsonOSB). Weyerhaeuser Weyerhaeuser Associated Chemists CONDITIONING ControlExample 4 Example 4 Inc. TIME (DAYS) No sealant (replicate 1) (replicate2) PFX99L94A 0  7^(a) (1)  8^(b) (1)  8^(b) (1)  8^(b) (1) 1 54^(a) (7)22^(b) (3) 22^(bc) (5) 18^(c) (4) 2 60^(a) (6) 32^(b) (5) 31^(b) (9)31^(b) (8) 3 (redry) 29^(a) (5) 10^(b) (5) 14^(b) (8) 14^(b) (6)

[0094] Note: numbers in parenthesis are standard deviation values. Thosedifferential edge swell values in a row that do not share a commonsuperscript are significantly (p<0.05) distinct at a 95% confidenceinterval.

[0095] While the preferred embodiment of the invention has beenillustrated and described, it will be appreciated that various changescan be made therein without departing from the spirit and scope of theinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A wood-based paneltreated with a composition for reducing edge swelling, the panel havingfirst and second major surfaces and four edge surfaces, the four edgesurfaces of the panel being treated with the composition, wherein thecomposition comprises (a) water, (b) a butylacrylate latex, (c) a wax,(d) an oil, wherein the wax is soluble in the oil, and (e) a surfactant,wherein the surfactant comprises an organic acid salt.
 2. The panel ofclaim 1, wherein the composition is applied to the edges at a spreadrate of about 25-50 wet pounds per Msqft of edge surface area and driedto yield a residue that substantially reduces differential edge swell.3. The panel of claim 1, wherein the composition comprises water in anamount from about 20 to about 60 percent by weight based on the totalweight of the composition; butylacrylate latex in an amount from about10 to about 25 percent by weight based on the total weight of thecomposition; wax in an amount from about 1 to about 25 percent by weightbased on the total weight of the composition, oil in an amount fromabout 2 to about 30 percent by weight based on the total weight of thecomposition; and a surfactant in an amount from about 1 to about 5percent by weight based on the total weight of the composition.
 4. Thepanel of claim 1, wherein the composition further comprises a secondlatex.